The detection of intravascular fat emboli (fat emboli are tiny globules of fat frequently found in the blood after a long bone fracture) following long bone fracture is necessary to insure timely therapy. The restriction or blockage of a blood vessel by a fat embolus can lead to the death of those body cells dependent on that circulation supply. The presence of fat emboli in the bloodstream, often referred to as the Fat Embolism Syndrome (FES), can cause pulmonary edema, apoplexy, or death.
The well-known continuous wave doppler ultrasonic flowmeter can be used to measure blood flow velocity and to detect gaseous emboli in the bloodstram. In recent experiments Kelly, Dodi and Eiseman have successfully detected the presence of fat emboli in the venous flow in the vicinity of a long bone fracture for a short period of time after the occurrence of the fracture. The detection is based on audio output of the flowmeter. A trained listener can hear certain "embolic sounds" in the audio output of the flowmeter. This work is described in Surgical Forum, Vol. XXIII (1972), pages 459-460.
The primary object of this invention is to provide a simple, reliable, robust and inexpensive technique to enhance and quantify the detection of FES in earliest stages.